How can we look at the beginning of the universe? If the light from the bing-bang explosion only reaching us *now*, does that mean that the universe expanded faster than the speed of light right after big-bang explosion? Wouldn't that violate einstein's theory of general relativity?
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1 How? Well, the universe was born 13.7bn or so years ago. So when we look at celestial objects 13bn light years away, we are seeing them as they were 13bn years ago, close to the birth of the universe. In fact, the oldest 'light' we can detect is the Cosmic Microwave Background Radiation, from about 100,000 years after Big Bang. See
http://en.wikipedia.org/wiki/CMBR
2 Did the universe expand faster than the speed of light? Yes - in what we know as the 'Inflationary Era'. See
http://en.wikipedia.org/wiki/Inflationar…
3 Does that violate Einsteinian relativity? No. The speed limit of c applies to objects moving in space-time, not to the behaviour os space time itself. All the same, it does remind us that there IS a problem. General relativity and quantum mechanics really aren't entirely compatible. One or other isn't quite right, or there is a major gap in our understanding. An understanding of the inflationary era depends on q mech, so it doesn't sit totally comfortably with general relativity.
http://en.wikipedia.org/wiki/CMBR
2 Did the universe expand faster than the speed of light? Yes - in what we know as the 'Inflationary Era'. See
http://en.wikipedia.org/wiki/Inflationar…
3 Does that violate Einsteinian relativity? No. The speed limit of c applies to objects moving in space-time, not to the behaviour os space time itself. All the same, it does remind us that there IS a problem. General relativity and quantum mechanics really aren't entirely compatible. One or other isn't quite right, or there is a major gap in our understanding. An understanding of the inflationary era depends on q mech, so it doesn't sit totally comfortably with general relativity.
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I'm having trouble understanding why you're thinking the universe expanded faster than the speed of light, but I don't think it did because that is the speed limit of the universe. And to the OzoneGuy- the universe did not accelerate. It has been slowing down ever since the Big Bang occurred. And telling someone that they are "so not thinking" is very rude.
So when cosmologists say we can look back to the beginning, they are talking about the leftover radiation that resulted from the Big Bang, which is everywhere in every direction we look in space...It has been cooling over time. Basically, that radiation tells us that our universe started at a single point and is great evidence for the Big Bang Theory itself.
So when cosmologists say we can look back to the beginning, they are talking about the leftover radiation that resulted from the Big Bang, which is everywhere in every direction we look in space...It has been cooling over time. Basically, that radiation tells us that our universe started at a single point and is great evidence for the Big Bang Theory itself.